Julian Assange poses a clear and present danger to American national security. The WikiLeaks founder is more than a reckless provocateur. He is aiding and abetting terrorists in their war against America. The administration must take care of the problem - effectively and permanently.

The recent WikiLeaks document dump is the latest example of Mr. Assange’s dangerous behavior. His release of more than 250,000 U.S. diplomatic cables, many of them containing classified information, is a major blow to our foreign policy. The essence of diplomacy - especially that of a great power - is the ability to conduct negotiations and hold talks in secret. Foreign leaders will not be willing to engage in sensitive discussions with American emissaries if their words are going to be splashed across the front pages of the world’s newspapers. Officials in autocratic and Islamist states often risk their lives to cooperate with Washington, usually by providing vital information or advice. They now face a further disincentive to help us: The U.S. government can no longer guarantee the privacy and secrecy of their discussions.

American diplomacy has been crippled. So has our ability to conduct the war on terrorism. For example, the cables cache reveals that the United States is working closely with Yemen’s dictator, Ali Abdullah Saleh, in launching drone strikes against local al Qaeda bases. Al Qaeda has spread to Yemen. Its insurgency is growing. Yemen risks becoming what Afghanistan was before Sept. 11, 2001: a vast sanctuary for jihadists. Mr. Saleh insists that Yemeni public opinion - insular, xenophobic and increasingly Islamic - will not support the U.S. military presence on domestic soil. Hence, he says the pretense must be maintained that Yemen is firing the missiles, not America. This pretense has been shattered - and with it, perhaps, a key ally in the struggle against al Qaeda. Mr. Assange is helping chase the American infidel out of Yemen’s desolate deserts.

This is what he wanted all along. The 39-year-old Australian poses as a champion of government “transparency.” He likes to grandstand for the media as an idealist, a brave whistleblower who only wants the truth to come out against U.S. “imperialism.” The Swedish government has accused him of sexually assaulting two women. Mr. Assange is an anti-American radical who wants to see the United States defeated by its Islamic fascist enemies. His goal is to humiliate America on the world stage, to drain it of all moral and legal legitimacy - especially regarding the wars in Iraq and Afghanistan.

Yet the Obama administration refuses to stop Mr. Assange. His previous document dumps disclosed the names and identities of foreigners working with the United States in Afghanistan and Iraq - individuals actively involved in defeating al Qaeda and the Taliban. Their exposure could lead to many of them being killed, tortured or targeted by insurgents. Mr. Assange is directly responsible for endangering their lives. He is an active, willful enabler of Islamic terrorism. He is as much a threat as Osama bin Laden or Ayman al-Zawahri. In short, Mr. Assange is not a journalist or publisher; rather, he is an enemy combatant - and should be treated as such.

As Mr. Assange has conducted cyberwarfare against America, President Obama has dithered. For months, he has insisted on viewing Mr. Assange as a public nuisance - nothing more, nothing less.

Instead, the administration should have pressured Australia to take decisive action against the leaker. It also should have issued an international arrest warrant and demanded that he be extradited to the United States to face charges of aiding terrorists. At a minimum, back in the summer, the administration could have launched a devastating cyber-attack against the WikiLeaks website, shutting it down.

Also, Pfc. Bradley Manning, who is suspected of being the main source for accessing the State Department’s treasure trove of classified information, was not interrogated aggressively. He should have been court-martialed immediately. The question that remains to be answered is: How did a low-level Army intelligence analyst get access to such detailed, privileged conversations? Who else helped him and why?

Mr. Obama, however, could not be bothered with any of this. For him, foreign policy is a distraction - something to be crammed into his schedule as he seeks to transform America into a multicultural social democracy.

The United States is paying a severe price for Mr. Obama’s negligence. This is the greatest diplomatic crisis since the late 1940s, when communist agents in the U.S. government provided atomic secrets to the Soviet Union. The world is witnessing the absurd, almost surreal spectacle of the American superpower standing helpless in the face of a lone hacker. Her diplomatic secrets are no longer safe; her allies and friends are being betrayed; and her cyber-enemies are free to roam with impunity. America is no longer feared or respected.

Attorney General Eric H. Holder Jr. vows that he is looking into possible criminal charges against Mr. Assange. It is too late for tough talk. At this point, we are beyond indictments and courts. The damage has been done; people have died - and will die because of the actions of this puerile, self-absorbed narcissist. News reports say the WikiLeaks founder is hiding out in England. If that’s true, we should treat Mr. Assange the same way as other high-value terrorist targets.

Jeffrey T. Kuhner is a columnist at The Washington Times and president of the Edmund Burke Institute.